Backpack work apparatuses have been conventionally known and used in the art, particularly in the cases of power-operated machines including a heavy work unit or tool. Among such backpack work apparatuses, JP 2008-002310 A discloses a backpack blower apparatus with a power-operated blower unit for blowing out air through an airflow tube. The disclosed backpack blower apparatus comprises a back carrier frame to be piggybacked or shouldered by an operator, an engine mounted on the back carrier frame, a blower unit driven by the engine, and an airflow tube fluidically coupled to the blow-out duct of the blower unit to blow out air from the distal end of the airflow tube. The backpack blower apparatus is provided with shoulder straps for piggybacking the back carrier frame.
In the case of the backpack blower apparatus disclosed in the above cited JP publication, the engine mounted on the back carrier frame is a kind of heavy machine, and therefore it would be preferable, if a chest strap is provided over the operator's breast to link the right and left shoulder straps to prevent the shoulder straps from slipping away from the shoulders, thereby stabilizing the shouldering conditions. In such a case, the chest strap would be fixedly connected to the right and left shoulder straps at its both ends and would be divided into two parts, a right and left pieces, at its center and releasably coupled together by means of a buckle device at the divided ends.
Linking the shoulder straps with a chest strap will help to stabilize the shouldering condition of the back carrier frame on the one hand, but may cause a kind of inconvenience of taking time to unshoulder the backpack apparatus on the other hand. In case of some trouble with the blower unit, it will be necessary to quickly unshoulder the piggybacked apparatus. Under such a circumstance, however, unbuckling the buckle device, pushing the right and left shoulder straps apart, and removing both of the shoulder straps from the operator's body would take a considerable length of time, and it would be accordingly hard for the operator to quickly get rid of the blower apparatus from his/her back.